Iftikhar Ahmad Randhawa

In a seminar organized by a renowned publishing group, in PC hotel Lahore in Summer 2012, I suggested Lahori’ites to arrange small sized biogas digesters in order to meet their gas demands in winter due to an impending shortage in the gas pipelines. The chief guest, a bureaucrat from Islamabad, did not agree to my concept and stated that my statement encroached upon the unification of the country and endangered the solidarity of Pakistan. Later in December, all Lahori’ites faced a severe reduction in gas pressure. Scarcity of gas in pipelines may increase and increase in future particularly in Punjab.

Discovery of abundantly available natural gas reserves in Pakistan did not allow Punjab to think about other technologies. Moreover, natural gas was a blessing of Almighty Allah which we burnt in inefficient stoves. Using the natural resource inefficiently is nothing less than a crime that we have been committing for years. Punjab produces only 5% of the natural gas and consumes 55% of the entire produce of Pakistan. As these reserves are now depleting fast, we need to think of other means for sustenance. Furthermore, Article 158 of the Constitution states that the Province in which a well-head of natural gas is situated shall have precedence over other parts of Pakistan, subject to the commitments and obligations as on the commencing day. Accordingly, as energy is a scarcity now, all provinces avail their constitutional right by catering to their needs first and supplying only surplus gas to Punjab. Punjab is being affected severely. The question arises what should Punjab do now? The solution lies in biogas.

Almighty Allah SBT says, “He who has made for you the fire (to burn) from the green trees so that with it you kindle” (Al Qur’aan: 36-80).We all know that before sending human beings on this planet, He arranged for all its needs of fodder, water, minerals, oxygen, environment and above all energy. Solar is one of the biggest sources of energy since millions of years. It serves as a large source of energy to the earth out of which fifty percent is absorbed by the oceans, plants, creatures and air while the rest is reverted to the universe. Energy stored in plants can be utilized by humans to meet their demands of heating and cooking food. There are two ways to utilize the energy stored in plants. One is incineration (burning) and other is biodegradation (methogenesis).  Harnessing energy through incineration is neither environment friendly nor hassle free.  Moreover, increase in carbon dioxide due to burning of fossil fuels and firewood is threatening the living species on this planet.  

On the other hand, biodegradation is a natural process. In this process, microbes, in the absence of oxygen, digest the material at a certain temperature and release certain gases from their body.  Underground reservoirs of gasoline and natural gases are the habitat of microbes. These microbes can be used artificially as well. When biodegradable materials such as grass, cow dung, straw, leaves, flour, paper, vegetables, human excreta, plastic or even metals are placed in a vessel with microbes, they can be converted to methane. Biodegradation takes time. Some materials may be degraded within twenty or thirty days whereas plastic, aluminum and tin may take two or three centuries. The vessel being used for this purpose is called ‘Biogas Digester’. This can be placed above or below the ground. Any seepage or leakage in the digester may hamper the biodegradation process resulting in failure.

Initially this technology could not attract the attention of masses as coal and other gasoline products were in use. However some individual level research and development remained intact. The growth of both large and small gas-fueled vehicles has been substantial around the world, particularly in Europe. In the United States, biogas is becoming quite a popular source of energy and wide varieties of feedstock   are being tested. It has been estimated that not only can the methane biogases derived from cattle, pigs and chickens manures  be used to power millions of homes around the world; they can also reduce billions of metric tons of greenhouse gas emissions. No other country in Europe generates as much power from biogas as Germany.  In 2010, the Federal Republic led the field in Europe with an output of some 16 billion kWh, followed by Great Britain (5.7 billion) and Italy (2.1 billion). This technology has also garnered support from the governments of various African and Asian countries. In Asia, China is the leader while Nepal and India follow. Chinese government took up the program in early fifties in order to promote biogas utilization to farmers in rural areas.  China further promoted the technology in 1970-80’s, by continuing to support the project.  In the period 2003-2013, the period of rapid development in rural areas, 41.68 million household small digesters (8-12m3), have been built. This technology in China is now being used for electricity generation by using waste water, animal farm waste, municipal waste, and agro waste.

Punjab, being agro based economy, has an immense potential of Biogas generation. It has 35 million livestock. This resource is not contiguous but is in fact distributed throughout the country.  From this livestock, 1225 mmcfd  gas can be generated per day which is  25 percent of  the national production of natural gas (4058 mmcfd). Production of biogas through other materials is not included in this estimate. Utilizing even 50% of the potential Punjab can cut down the energy problems considerably. By generating the same for stoves, a lot of natural gas can be saved for electricity production even at a national level. There is a scope of 5-8 million household biogas digesters in Punjab. A 10 cubic meter digester uses 100 kg dung daily (obtained from 7-8 Cow heads) and supplies 6-8 m3 gas per day which is sufficient to cook three meals for a family of five or six. One m3 gas can produce heat equal to 1kW heater for one and a half hour.  

Government of Pakistan undertook propagation of Biogas Technology early in 1976. Initially, 1200 family size units were installed.  The biogas digesters adapted at that time were known as Indian style digesters. This style is constant pressure type. A deep rounded well is dug in the ground and lined with bricks and cement. A round steel drum is turned upside down and fitted as a lid on the mouth of the well.  Gas is collected in this drum. Gases lift the drum up and after they are used, drum moves downward.  This program could not attract attention mainly because life of the drum was low and daily filling of cow dung was a hassle. Discovery of natural gas was also a hurdle in the promotion of biogas as it was easy and hassle free to use.  Government of Pakistan established Pakistan Council of Renewable Energy Technologies (PCRET) which launched another project for installation of 2,500 biogas plants in 2007 with a subsidy component of Rs.17000/- per plant. In two years, despite various financial constraints, about 2,000 biogas units have been installed. As mentioned earlier, a major drawback in the Indian digesters was the steel drum. Presence of H2S in the produce cracks it within two or three years. Replacement of steel drums is a cost which is difficult to bear just like the cost of batteries in the small off-grid solar solutions.  Its installation also requires high expertise of craftsmanship. It costs round 13-15 thousands rupees per cubic meter. 10, 12, 15 and 20 m3   sizes are commonly used.   High initial cost and high operational cost are the barrier in the adaptation of the Indian style digesters.

In 2010, Rural Support Program Network (RSPN) initiated Pakistan Domestic Biogas Program. This program aimed to develop the domestic biogas sector. Sector development implies close cooperation and coordination of all relevant stakeholders (government, non-government and private sector) at micro and macro levels.  The proposed project was designed to put down a robust foundation for the establishment of a commercially viable domestic biogas sector. The proposal used a time horizon of 4 years to strengthen the commercial biogas sector. Although the project aimed to promote an approach in which government, non-government and private sector organizations assumed their roles in a complementary fashion that intrinsically fit their character; this did not catch eyes of the masses. Only 5000 dome type digesters have been constructed in addition to training about 500 local masons.

Dome type digesters are made of bricks and cement and involve fixed volume principle. No drum is used as a lid in this technology. Cost of such digesters range from 8 to 10 thousands rupees per cubic meter which is cheaper than Indian style digesters. However these digesters also require highly skilled craftsmanship and are built in 20-25 days. Common designs are in 6, 8, 10, 15 and 20 cubic meters. Leakage and seepage are frequently encountered problems but can be corrected with good maintenance and training. However once the digester leaks or seeps, it is difficult to be rectified.

Punjab has also launched a program to subsidize 20000 biogas plants of 30, 50 and 70 cubic meter for the farmers to supplement their diesel engines for water pumps. The design submitted by the consultant is of both Indian and dome type digesters.  The cost for system installation is 12-14 thousand rupees per cubic meter which is quite high. The construction time is around 25-30 days per team for one digester. Project is at infancy stage yet.

High cost, time consuming construction activities and requirement of high quality craftsmanship are major barriers in the adaptation of dome type digesters.  Stakeholders are enmeshed in a supply and demand context in which the supply side should ensure “off-the-shelf availability” of the technology while the pluralistic demand side organizes the beneficiaries, provides microfinance, promotes the technology and integrates it into rural development activities. For this purpose, many Chinese company have established a soft type digester.  A tank is dug in the ground as per desired dimensions according to size of the digester. Construction of tank does not require skilled workmanship and even a normal mason can accomplish the task. The soft type digester can then be fixed in the tank. This installation takes only four days for tank and two hours for digester fixation. The cost is 5-6 thousand rupees per cubic meter. A Chinese company has installed many demonstration digesters in Pakistan, the list of which can be provided to any party that is interested. A Chinese company has also decided to establish an office in Lahore. This is a good chance for all Punjabis to undergo a paradigm shift. Punjab has always been a leader in introducing and promoting new ideas. If Punjab is green, entire Pakistan would be green. So let us harness biogas to the most of its potential and make Punjab green and prosperous.