Every now and then a report gets published that makes me annoyed. Boeing reveals “the biggest breakthrough in biofuels ever”, published by Energy Post last week, and evidently read by >95,000 people in a single day was one them.
Oil companies watch out. Biofuels are on the verge of a breakthrough that will transform the oil market. Not only that: it will also green the planet.
Morgan is not some green dreamer. He is Director of Sustainable Aviation Fuels and Environmental Strategy at The Boeing Company in Seattle in the US. He has worked on Boeing’s biofuels program for 10 years. And he is convinced that researchers at the Masdar Institute, sponsored by Boeing, Honeywell’s UOP and Etihad Airways, have achieved a breakthrough in biofuels that will make it possible for countries all over the world to turn their deserts into biofuel-producing agricultural lands.
The consortium then decided to set up a pilot production facility which is now being built in Abu Dhabi right next door to Masdar City. There is yet one more element to this to complete the story, because what the researchers decided to do in this pilot project is also unique: they decided to combine the production of biofuels from halophytes with aquaculture.
I’m afraid that whenever I read about Green strategies designed solely to reduce CO2 emissions that otherwise show little regard for the natural environment and delicate ecosystems, my hackles rise. Karel Beckman, the author of the Energy Post piece provided a link to a Power Point authored by Professor Robert Baldwin which shows some potentially interesting engineering and science behind the incredible claims. And so let me begin with a critical look at what this is all about. At the end I pose a number of fundamental questions, the answers to which are required for any evaluation of this “breakthrough” to be made and I’m hopeful that Professor Baldwin may respond.
The integrated seawater agriculture system (ISAS)
At the heart of this “breakthrough” lies a plant called Salicornia that grows in deserts and is tolerant of salt water and has potential as a bio fuel. A major problem with temperate latitude biofuels is their use of agricultural land and fresh water (and also pesticides and ammonia based fertilizer made from natural gas) and so it is proposed to over come these problems by growing biofuels in the desert irrigated with salt water – too good to be true? And all this is to be done in a Green sustainable way.
The second part of the story is to have aquaculture tanks rearing fish (Tilapia) and shrimps at the front end, all the faecal waste from this operation to be pumped to the Salicornia beds where the faeces provide nutrients.
The system diagram (Figure 1) indeed shows some serious thought has been put into this scheme. So what could possibly go wrong?
Figure 1 Process diagram and flow for the ISAS system. This may be broken down into 3 main components: aquaculture to the left, Salicornia and mangrove farming in the centre, fuel refining and processing to right.
Energy Return on Energy Invested (ERoEI)
In the energy world there are two forms of energy extraction. The first, and by far the most important is primary energy extraction, for example oil and gas and hydro electric power. These provide the energy surpluses that run society. The second is energy conversion where one type of energy source is converted into another. The best example of this is electricity production from coal, gas and nuclear where the thermal energy from these sources is converted to electricity. Surprisingly, temperate latitude bio-fuels are also an energy conversion where natural gas is converted to fertilizer and then to corn and then ethanol. There is virtually zero energy gain and the process is enabled by mandates and Americans placing a higher value on liquid fuel than natural gas.
In the ISAS system I count 16 energy inputs
- Electricity to pump water into fish ponds
- Electricity used in shrimp hatchery and feed production
- Electricity used in Tilapia hatchery and feed production
- Electricity used in shrimp farming and processing
- Electricity used in Tilapia farming and processing
- Electricity used to pump water and ecscrament to the Salicornia fields
- Additional fertilizer production and transport
- Diesel used during planting
- Diesel used during harvesting
- Transportation of harvest to Biomass facility
- Pumping “treated seawater” back to the ocean
- Electricity used in biomass facility
- Energy used in the Oil processing facility
- H2 production (from what?) and transport to Oil Processing Facility
- Transport of “renewable” jet fuel to market
- Energy used to construct fish ponds, hatchery, irrigation system, biomass facility, oil process facility etc.
While electricity could conceivably be made from solar or nuclear power in the UAE, the most likely source right now will be crude oil or natural gas. At the outset I would therefore voice concern that this may be an extremely elaborate and expensive way of converting fossil fuel into a bio-jet-fuel. Temperate latitude bio fuels tend to have ERoEI ~ 1 while tropical sugar cane ethanol has ERoEI ~ 6. If one is willing to set aside the use of rainforest to grow liquid fuel, then the latter is worth while, the former is not. The first hurdle that the ISAS system needs to clear, therefore, is demonstration of a large, positive net energy (net energy = ERoEI-1). If ISAS is net energy negative then the outcome would result in turning more fossil fuel into less bio-jet-fuel and harming the desert environment en route.
The salination of soils
Figure 2 shows the cultivation set up with irrigation pipes and Salicornia plants growing in the desert sand. Here I have to presume that the irrigation pipes seep water to the plants either continuously or periodically. And this is salt water that is being applied, and when it evaporates leaves behind a salt residue that will build up over time eventually destroying the soil. Prof. Baldwin’s presentation does flag “salt management” as an issue.
Figure 2 Salicornia growing in desert soil alongside salt water irrigation pipes. The water applied evaporates leaving behind a salt residue that will inevitably accumulate in and eventually destroy the soil.
Figure 3 taken to an extreme, too much salt will develop a salt pan, one of the most arid and hostile desert environments on earth.
Taken to an extreme, adding too much salt water to a desert soil will form a salt pan, creating a totally arid and sterile environment. How does the Masdar consortium propose to mitigate this problem?
Salinity control and fresh water supply
Average seawater has a salinity of 35 g / l, i.e. 35 parts per thousand (ppt). The experimental results from the Masdar Institute team shows optimum productivity of Salicornia at salinities of 20 ppt suggesting that to optimise the system, large amounts of fresh water are required to dilute seawater. Freshwater seems also to be required for germination of the plants (Figure 4). In the world’s deserts, where is this freshwater to come from? Furthermore, since it is to be reasonably anticipated that the soils are to become enriched in salt over time, how will this impact productivity and be mitigated?
Figure 4 Productivity is closely linked to salinity of irrigation water. It is interesting to note that Salicornia seems to thrive on salt water with optimum productivity at 20 parts per thousand. However, salt will quickly accumulate in the soil producing high salinities even when lower salinity water is applied.
Salt water supply
The leading article gives the impression that the worlds deserts can be transformed into industrial scale bio fuel agricultural systems when in fact, the need for salt water seems to limit this developmental concept to coastal regions given the high energy and financial cost of building corrosion resistant pipelines and pumping water.
One of the most important questions to ask is on yields. How much desert has to be used to produce a barrel of Green jet fuel?
This question is perhaps best reduced to “How many acres of desert are required to produce sufficient jet fuel for a single flight from Abu Dhabi to New York?” Ultimately, we need to ask the question, what will a barrel of bio-jet-fuel cost?
Assessing environmental impact gets to the heart of the matter. The world’s deserts are delicate and important ecosystems. This proposal will likely destroy this environment where the technology is deployed. And so we need to know how many acres of coastal desert need to be given over to Salicornia production to make a significant impact on global jet fuel consumption. This links to the yield question above.
And one final point, evaporating seawater in the desert will cause a very powerful greenhouse warming that may disrupt local weather systems. Not to mention the change in albedo. Are these factors taken into account in this pursuit of mitigating climate change?
Questions for Professor Baldwin
And so to my questions for Professor Baldwin, the author of the presentation at the heart of this critique.
- What is the ERoEI of the ISAS system? This may be reasonably adjusted for the fish production output benefit, but should also account for thermal losses in power generation plant, or for fossil fuel inputs to the manufacture of solar panels etc.
- How will desert soils cope with irrigation by salt water? How will this be mitigated?
- Where does the fresh water supply for the system come from?
- Is this process restricted to coastal deserts where there is a salt water supply?
- How many hectares of desert are required to provide bio-jet-fuel production to fuel a single Boeing Dreamliner (or equivalent) trip from Abu Dhabi to New York?
- How is converting pristine desert to industrial scale bio-jet-fuel production Green, sustainable and of benefit to global society?
- What are the estimated local climatic impacts of evaporating large amounts of water over dry desert?
I have absolutely no objection to the financially and energy wealthy UAE experimenting with desert bio-jet-fuel production systems as described in ISAS. It is sometimes the case that allowing individuals to think out of the box like this, unconstrained by finance or energy (laws of thermodynamics) that some significant scientific breakthroughs may be made. What I object to is embroyonic research being presented by Energy Post as the biggest break thorough for bio-fuels ever, in an environmentally sustainable way, when none of the data to support these spectacular claims are offered.
Figure 5 The Greening of desert Masdar style. The picture I believe shows algae cultivation. The UAE may well wish to plan for the day when their oil production begins to decline and using their deserts for energy production may be justifiable to meet that end. Arguing that habitat destruction is somehow Green and sustainable, is not.