By Lanre Lawal PhD, FRGS, FHEA, MIEnvSc, MifL
Gas flaring (GF) and venting represents one of those activities which have dire consequences for humans, the environment and the planet.GF emanates from various industries (e.g. gas processing plants, liquefied natural gas terminals, oil refineries, petrochemical plants), however in Nigeria is it is most especially from combustion of associated natural gas from crude oil extraction (Figure 1). Between 1995 and 2006, it was reported that annually a total of between 150 and 170 billion cubic metres (BCM) of associated gas was flared across the globe. The impact of this has been tremendous, especially across the Niger Delta resulting in extensive degradation of the environment which often leads to social uprisings. For example, studies have shown that there is retardation of crop growth, decreased yields. Furthermore, GF has also been linked to the pervasiveness of social miscreants and antisocial behaviours and increased rate of corrosion of Zinc roof in areas near gas flaring or sea aerosol (Ekpoh & Obia, 2010). The body of knowledge on the impact is extensive. Several administration have tried using various instrument of legislation to stop and discourage GF, however, despite all these GF has continued unabated.
Is there any other alternative to flaring of the associated gas from our oil and gas industry? The answer is a clear YES! Globally, there are a number of technologies available for utilisation of associated gas instead of flaring. Gas-To-Liquid (GTL) and Natural gas hydrate are some of the technologies currently popular. Several works have examine the adequacy, efficiency and cost-benefit analyses of GTL (Bao, El-Halwagi, & Elbashir, 2010; Chedid, Kobrosly, & Ghajar, 2007; Onwukwe Stanley, 2009; Reddy Keshav & Basu, 2007). Natural gas hydrate provides an opportunity for natural gas or associated gas to be transported efficiently to points of potential utilisation. Despite the fact that GTL is a proven technology, and can produce high quality fuels and chemical feedstock products (e.g. Naphtha, Diesel, Jet fuel, Kerosene, Wax and Lube), the technology has not been fully harnessed in Nigeria. Currently there is only one project in this respect in Nigeria, theEscravos GTL plant in Escravos with a capacity of about 33,000 barrels per day.
Recently, some countries have been very successful in converting associated gas that would have been flared into power. On the M’Boundi oil field in the Republic of Congo, associated gas feeds two power plants through a 350MW gas to power project and supplies electricity to over 300,000 people (Yesyrkenov, 2012). Rosneft recently was received an award for reducing gas flaring at it’sKomsomolskoye oil field. Rosneft installed compression station to treat and produce clean natural gas (Yesyrkenov, 2012). This project was implemented under the Joint Implementation Project – one of the mechanism of the Kyoto Protocol. A unique example can be seen in the Kuwait Oil Company. The company managed to utilise almost 99% of the associated gas produced, with significant economic (increasing electricity production to meet demands and services gas demand) and environmental benefit(World Bank, 2014).
MiniGTL technologies are one of the most promising in addressing the utilisation of gas flaring. According to Fleisch (2012), there are technologies that are applicable to flares ranging from very small (below 0.5MMscfd) to large flares (10MMscfd and above) as well as for onshore and offshore applications. There has been a growing number of options in technologies and companies offering solutions to potential customers burdened by gas flaring problems or marginal fields. This has significantly increased the financial attractiveness of MiniGTL via the reduction of the capital expenditure(Fleisch, 2014).
The work of Fleisch (2014) examined several companies and their MiniGTL technology offerings. The work carried out comparisons based on plant scale applicability, base plant parameters, risk and commercial readiness of these companies and their technologies. The work aim at providing support for GGFR members in the identification of viable, and low risk option for reducing gas flaring.
According to the World Bank (2004)there are four viable options for the utilisation of associated gas:
a. Production of power at the location for transmission to existing power grid
b. Power production on location for electrification of nearby communities
c. Supplying large gas consumers (heat and power plants) via pipelines
d. Conversion to liquefied petroleum gas, solely or combined with other mean of use
Options (a) and (c) are suitable for medium-scale utilisation while options (b) and (d) are suitablefor small scale utilisation. Furthermore, they concluded that options (a) and (b) are the most relevant (with a possibility of combining them with option (d)) for many countries in the tropics and subtropics due to their peculiar circumstances. Further findings by the World Bank (2004) shows that subsidies are not essential in order to achieve economic and financial viability of such endeavour. However, if markets are far away or gas deposits are small or there are price distortion due to domestic fuel subsidies, there may be a consideration for subsidies to stimulate the development of associated gas utilization investments. Their comparison also shows that there is little economic difference between transporting gas via pipeline to existing power plant and generating power on location then transmitting via power lines to load centres.
Using a benchmark of about 15MMscfd gas feed rate, foot print ranges between approximately 1 acre and 5 acres for MiniGTL process unit. For this, production volume of between 1300 and 1500 barrel per day (bdp) can be expected. It must be noted that the smaller the plant the lower the process efficiency. Capital expenditure (Capex) stands at around $100,000 daily barrel capacity (dbc) with cost likely to be higher for smaller sized plant. However, some companies have demonstrated that it is possible to build plant for about $100,000/dbc(Fleisch, 2014). While operating expenditure (Opex) was estimated to around $20 per barrel, the company INFRA claimed that their technology is able to significantly lower the Opex by fourfold. Energy efficiency ranges between 50% and 65%, while carbon efficiency ranges between 60% and 90%.
OBERON, GREYROCK, CompactGTL, VELOCYS, Marcellus GTL and GASTECHNO have significantly lower over risk and a shorter time to commercialisation of their technologies. While OBERON, GREYROCK, CompactGTL and VELOCYS are the leaders in the field with lower risk and higher readiness for commercialisation of their technologies. These four have are well managed and possess strong financial backers as well as a solid financial base proven technologies and experienced staffs (Fleisch, 2014). With low Capex for application below 1MMscfd, GasTechno, Proton Ventures and R3Sciences have worthy technologies however with some technology risk.
With all this options and technology available, some of the questions that comes to mind includes:
a. How do we identify viable locations?
b. Which options are the most viable?
c. How do we get investors into this area?
The opportunities are tremendous, if only we are ready to be innovative and challenge the status quo. Firstly using advances in Geographical Information Science and Remote Sensing we can assess viability of different flare sites. With this assessment we can also be able to identify suitable options for each sites. One option that can be exploited in dealing with the economic side of the implementation would be to use some of the mechanism within the Kyoto Protocol. If there is a will there is always a way!
Figure 1: Spatial Distribution of gas flaring recorded by VIIRS measurement between 2013 and 2014
Source: Authors' representation and Google map imageries
Lanre Lawal PhD FRGS FHEA MIEnvSc MifL
Bao, B., El-Halwagi, M. M., & Elbashir, N. O. (2010). Simulation, integration, and economic analysis of gas-to-liquid processes. Fuel Processing Technology, 91(7), 703-713. doi: http://dx.doi.org/10.1016/j.fuproc.2010.02.001
Chedid, R., Kobrosly, M., & Ghajar, R. (2007). The potential of gas-to-liquid technology in the energy market: The case of Qatar. Energy Policy, 35(10), 4799-4811. doi: http://dx.doi.org/10.1016/j.enpol.2007.03.017
Onwukwe Stanley, I. (2009). Gas-to-Liquid technology: Prospect for natural gas utilization in Nigeria. Journal of Natural Gas Science and Engineering, 1(6), 190-194. doi: http://dx.doi.org/10.1016/j.jngse.2009.12.001
World Bank. (2014, 08/25/2014). Gas utlization in Kuwait reaps economic and environmental benefits. Retrieved 6th of May, 2015, from http://www.worldbank.org/en/news/feature/2014/08/25/gas-utilization-in-kuwait-reaps-economic-and-environmental-benefits
Yesyrkenov, Y. (2012, 10/25/2012). Rosneft wins award for gas flaring reduction efforts in Russia. Retrieved 6th of May, 2015, from http://blogs.worldbank.org/energy/gas-flaring-reduction-makes-life-better-for-the-people-of-gubkinskiy