Refining biomass into liquid fuel
The palm oil plantations in Malaysia are massive green swaths that stretch up into the mountains in the horizon. The largest plantations are one million hectares and they produce enormous amounts of waste. The empty palm bunches, left over after the palm fruit has been stripped out, are heaped into huge compost piles that sometimes catch fire.
In the capital city of Kuala Lumpur in June, smog caused by fires at farming operations, including palm oil plantations, is so thick even the Petronas Towers disappear into the haze. Because the palm oil industry is so immense (producing more than 50 million tons of oil annually) and economically critical to the region, it is extremely difficult for local officials to limit the pollution.
But one company has come up with a refined plan to reduce palm oil biomass waste and create a marketable biofuel from it. The underlying technology – which was developed by Shell Oil over several years – will allow NextFuels and its partners to produce bio-based petroleum at commercial scale for $75 to $85 a barrel out of wet biomass that has not been mechanically or thermally dried.
“We have a long association and contact with the palm oil industry in both Indonesia and Malaysia and we were looking for a non-food resource biofuel – a drop-in biofuel – and we were aware of an enormous amount of waste generation in the palm oil industry and its negative environmental affects,” says Dr. Ralph Overend, chief scientist at NextFuels.
The company is collaborating on its commercial strategy with Enagra, a biofuel trading company with extensive contacts and partnerships throughout the industry, on the development of its technology. The two companies are owned by the same investors and managed by executives with extensive experience in biofuels. Over the past 10 years, Enagra has conducted over $1 billion in biofuel transactions and will achieve revenues of approximately $150 million in 2013.
Ubiquitous Palm Oil
Palm oil is in just about every manufactured food product made in the U.S. and Europe. In Africa and Southeast Asia it has surpassed soybean to become their primary cooking oil. The oil palm tree is a perennial, which means it has an enormously high productivity. Unlike the annuals – like soybean and rapeseed – the oil palm tree stays from year to year and has a yield as high as 7,250 liters per hectare per year.
Approximately 4.4 to six metric tons of agricultural waste is generated for each metric ton of oil. There are over 1,000 crude palm oil (CPO) mills in Southeast Asia and a single (60 tons per hour) mill can generate 135,000 tons of agricultural residues a year.
“The palm oil has great value, but the solid waste is a major problem,” Overend says. “There is pressure on the mills to be environmentally correct and they are composting the biomass. But the compost piles do catch on fire and generate the haze in Southeast Asia. I could barely see the Petronas Towers from the hotel next door the last time I was there because of the haze.”
Frank Hughes, NextFuels vice president of business development, director of marketing, recently met with Malaysian officials from the Office of Innovation and Technology in Kuala Lumpur, who told him that the palm plantations are actively looking for ways to either dispose of properly, or monetize the enormous amounts of biomass that they create.
“From every discussion we have had with existing palm plantations they would be open to a technology like this that could come in and solve their residue and waste issues,” Hughes says.
The technology and process NextFuels uses is a system called bio-liquefaction that efficiently transforms agricultural biomass to green energy. Biomass is placed into the plant mixed with water. The mixture is then heated to 330 degrees Celsius while pressure is increased to 220 bar. Increasing the pressure keeps the water from coming to a boil, which conserves energy.
“This is a highly efficient process and except for a small amount of electricity to drive the pumps and circulators, there are no other energy inputs, we use the biogas from the water stream,” Overend says. “The process is delightfully simple, of course, everything depends on the execution.”
When cooled, the hydrocarbons form a putty-like substance called GreenCrude. Roughly 25 percent of the GreenCrude can be burned as a solid fuel in industrial boilers. The remaining 75 percent can be converted into a liquid-fuel equivalent to petroleum that is compatible with existing pipelines and vehicles. The equipment required to convert GreenCrude into liquid fuels, in a process called hydrodeoxygenation, is already installed at most refineries and can accept GreenCrude with minor refinements.
Unlike other biofuels processes, this one does not need to dry the biomass before processing. The process is uniquely and specifically designed to work with wet biomass. As a result, the energy balance achieved is approximately 65 to 70 percent, or 65 to 70 percent of the energy put into the system becomes useable energy.
“We do find some skepticism, but it is a well researched process and other people have been trying to develop it over the years as well,” Overend says. “There's a good body of knowledge that supports this technology.”
NextFuels is currently raising capital to rebuild a bio-liquefaction demonstration plant originally created by Shell in 2005. The system ran for over 1,000 hours and is capable of producing five to eight barrels of oil a day. Enagra and others will finance the cost of reassembling it and demonstrating production over the next 18 months.
Within two to three years, the company anticipates it will start to build its first commercial scale modules capable of producing 250 barrels of oil equivalent a day. Four modules capable of producing 1,000 barrels of oil equivalent a day will be the typical size of a plant. Commercial scale modules may initially cost approximately $20 million.
NextFuels will partner with plantation owners and others on various projects. The company estimates that transforming residue into fuel could raise the value of plantation real estate by 30 percent or more per hectare.
“There is no such thing as waste,” said Dr. Overend. “The biofuel industry has been hampered by technological and economic challenges. We believe our system helps overcome many of these problems.”
According to Overend, the final product of drop-in biofuel will meet full fuel specifications and the markets for it will be ones that will pay a premium for the renewable carbon in the product. If the process works as well as Overend believes it will, then the next time he visits Kuala Lumpur he will have a clear view of the stainless steel Petronas Towers glint and shine in the sun.
Why Transmission & Distribution Utilities Need Digital Twins
As with any new technology, Digital twins can create as many questions as answers. There can be a natural resistance, especially among senior utility executives who are used to the old ways and need a compelling case to invest in new ones.
So is digital twin just a fancy name for modelling? And why do many senior leaders and engineers at power transmission & distribution (T&D) companies have a gnawing feeling they should have one? Ultimately it comes down to one key question: is this a trend worth our time and money?
The short answer is yes, if approached intelligently and accounting for utilities’ specific needs. This is no case of runaway hype or an overwrought name for an underwhelming development – digital twin technology can be genuinely transformational if done right. So here are six reasons why in five years no T&D utility will want to be without a digital twin.
1. Smarter Asset Planning
A digital twin is a real-time digital counterpart of a utility’s real-world grid. A proper digital twin – and not just a static 3D model of some adjacent assets – represents the grid in as much detail as possible, is updated in real-time and can be used to model ‘what if’ scenarios to gauge the effects in real life. It is the repository in which to collect and index all network data, from images, to 3D pointclouds, to past reports and analyses.
With that in mind, an obvious use-case for a digital twin is planning upgrades and expansions. For example, if a developer wants to connect a major solar generation asset, what effect might that have on the grid assets, and will they need upgrading or reinforcement? A seasoned engineer can offer an educated prediction if they are familiar with the local assets, their age and their condition – but with a digital twin they can simply model the scenario on the digital twin and find out.
The decision is more likely to be the right one, the utility is less likely to be blindsided by unforeseen complications, and less time and money need be spent visiting the site and validating information.
As the energy transition accelerates, both transmission and distribution (T&D) utilities will receive more connection requests for anything from solar parks to electric vehicle charging infrastructure, to heat pumps and batteries – and all this on top of normal grid upgrade programs. A well-constructed digital twin may come to be an essential tool to keep up with the pace of change.
2. Improved Inspection and Maintenance
Utilities spend enormous amounts of time and money on asset inspection and maintenance – they have to in order to meet their operational and safety responsibilities. In order to make the task more manageable, most utilities try to prioritise the most critical or fragile parts of the network for inspection, based on past inspection data and engineers’ experience. Many are investigating how to better collect, store and analyze data in order to hone this process, with the ultimate goal of predicting where inspections and maintenance are going to be needed before problems arise.
The digital twin is the platform that contextualises this information. Data is tagged to assets in the model, analytics and AI algorithms are applied and suggested interventions are automatically flagged to the human user, who can understand what and where the problem is thanks to the twin. As new data is collected over time, the process only becomes more effective.
3. More Efficient Vegetation Management
Utilities – especially transmission utilities in areas of high wildfire-risk – are in a constant struggle with nature to keep vegetation in-check that surrounds power lines and other assets. Failure risks outages, damage to assets and even a fire threat. A comprehensive digital twin won’t just incorporate the grid assets – a network of powerlines and pylons isolated on an otherwise blank screen – but the immediate surroundings too. This means local houses, roads, waterways and trees.
If the twin is enriched with vegetation data on factors such as the species, growth rate and health of a tree, then the utility can use it to assess the risk from any given twig or branch neighbouring one of its assets, and prioritise and dispatch vegetation management crews accordingly.
And with expansion planning, inspection and maintenance, the value here is less labor-intensive and more cost-effective decision making and planning – essential in an industry of tight margins and constrained resources. What’s more, the value only rises over time as feedback allows the utility to finesse the program.
4. Automated powerline inspection
Remember though, that to be maximally useful, a digital twin must be kept up to date. A larger utility might blanche at the resources required to not just to map and inspect the network once in order to build the twin, but update that twin at regular intervals.
However, digital twins are also an enabling technology for another technological step-change – automated powerline inspection.
Imagine a fleet of sensor-equipped drones empowered to fly the lines almost constantly, returning (automatically) only to recharge their batteries. Not only would such a set-up be far cheaper to operate than a comparable fleet of human inspectors, it could provide far more detail at far more regular intervals, facilitating all the above benefits of better planning, inspection, maintenance and vegetation management. Human inspectors could be reserved for non-routine interventions that really require their hard-earned expertise.
In this scenario, the digital twin provides he ‘map’ by which the drone can plan a route and navigate itself, in conjunction with its sensors.
5. Improved Emergency Modelling and Faster Response
If the worst happens and emergency strikes, such as a wildfire or natural disaster, digital twins can again prove invaluable. The intricate, detailed understanding of the grid, assets and its surroundings that a digital twin gives is an element of order in a chaotic situation, and can guide the utility and emergency services alike in mounting an informed response.
And once again, the digital twin’s facility for ‘what-if’ scenario testing is especially useful for emergency preparedness. If a hurricane strikes at point X, what will be the effect on assets at point Y? If a downed pylon sparks a fire at point A, what residences are nearby and what does an evacuation plan look like?
6. Easier accommodation of external stakeholders
Finally, a digital twin can make lighter work of engaging with external stakeholders. The world doesn’t stand still, and a once blissfully-isolated powerline may suddenly find itself adjacent to a building site for a new building or road.
As well as planning for connection (see point 1), a digital twin takes the pain out of those processes that require interfacing with external stakeholders, such as maintenance contractors, arborists, trimming crews or local government agencies – the digital twin breaks down the silos between these groups and allows them to work from a single version of the truth – in future it could even be used as part of the bid process for contractors.
These six reasons for why digital twins will be indispensable to power T&D utilities are only the tip of the iceberg; the possibilities are endless given the constant advancement of data collection an analysis technology. No doubt these will invite even more questions – and we relish the challenge of answering them.