Biogas from fodder grass (Napier).
Islamabad: We are going through difficult times with regard to energy supply and prices. Energy supplies are diminishing and global energy prices are rising.
It has become vital for us to search for and discover as many energy resources as possible. Climate change issues also require developing renewable energy sources and reducing the use of fossil energy sources.
In addition, new energy sources should also contribute to increasing income and employment opportunities for people. And perhaps finally, resources should be local to avoid draining foreign exchange.
We have discussed various energy sources in this field and emphasized on development and utilization of biogas resources and identification of a variety of fuels such as organic waste, municipal solid waste (MSW), food waste, agricultural and industrial biowaste, etc. In this space, we will talk about the use of elephant grass due to its great height.
A new source of energy has recently been discovered. Napier grass is named after the developer and is commonly called elephant grass or Sudanese grass.
Fodder grass is well known and used for animal feed. But elephant grass is a new species that produces several times more production than regular grass. It can be produced five times a year. It requires less water and can be grown in arid areas.
Elephant grass is grown in Thailand, India, Africa and elsewhere. In Thailand, they started producing biogas from it. India has also made plans to start producing biogas from elephant grass.
Biogas production from elephant grass has been reported to be 90-150 cubic meters per tonne. However, being a cellulosic material, elephant grass must be pre-treated with 1% NaOH for 24 hours to enable it to undergo conventional digestion as generally occurs in biogas production.
Elephant grass can also be mixed with other traditional waste materials such as cow dung, food waste, organic waste, etc. In fact, the biogas production with a mixture of waste with elephant grass is higher than with individual elephant grass material.
However, elephant grass is a warm-season growing material. There must be an alternative material to replace it when it is not available. Arid areas with agricultural activities such as those in Balochistan are likely to be suitable for this. It would help both local energy (biogas) and fodder for animal husbandry and pasture management activities.
New technologies are in development, one of which has increased yield by 100%, reducing land requirements by half. Recent figures indicate 120 acres of land for a five-tonne-per-day CNG plant.
Likewise, elephant grass production has been reported to increase from 150-200 tons per acre to 350-400 tons. In India’s Gujarat state, 10-tonne-per-day biogas plants based on elephant grass are being developed. Some should have started working too.
is reading Lahore is home to one of the largest biogas plants in the country
Objection to the use of biomass for energy
One common objection against using biomass for non-food/energy purposes is that it diverts land and water resources from food production.
The population of developing countries is increasing, and with it the demand for food. Therefore, only barren or low-value land is allowed for energy crop purposes.
Fortunately, elephant grass has both uses; Feed for livestock, biogas and biofuel for energy. In order to develop a policy in this regard, one has to conduct a site survey where these criteria are met.
In Pakistan, elephant grass production has begun recently. It is used for fodder purposes. Elephant grass reaches a height of 10 to 12 feet, almost twice the height of natural forage grass. Thus, the production and income of farmers increases. Elephant grass can also be used to make energy bars. These briquettes are used at home for cooking and heating in rural areas. Small rural industry also uses these molds. This results in less trees being cut down as well.
Pastures are usually arid with little rainfall. In Pakistan, 60% of the land area is classified as pastureland. Grassland areas support livestock and wildlife production. It has been reported that only 15% of this area is normally exploited and the rest is degraded. This represents huge potential for livestock and biomass production; Hence likewise the potential for production of elephant grass and biogas.
There are areas in Pakistan where fodder can be produced but there is no or less market for animal food. Elephant grass production can boost the animal husbandry industry besides boosting energy supply.
The opposite may also be true. The energy market should be able to provide all types of energy resources that match demand and available resources. Elephant grass has the ability to reduce the consumption of fossil fuels such as LPG, kerosene and even coal. It can reduce the polluting footprint of rural industries such as brick kilns.
Finally, people wonder why we cannot take advantage of many of the local resources that have been identified. Government, industry, academia and R&D institutions need to cooperate with each other.
Often the issues are multidimensional. The user is from one sector and the product belongs to another sector. Investors are reluctant to invest in new areas. It requires firm policy and facilities.
Also, sometimes, the government has to take the first step to set up a model factory. This will also enable estimates of the economics of biogas production through elephant grass.
Each region has different resources and comparative energy prices vary. Therefore, it is important to do this exercise. The most important issue in its subject is determining the optimal location from an agricultural point of view. These days, there is a great deal of international interest in renewable energy resources. Carbon finance markets and grants are available. The government is required to form a committee to carry out advance work.
The writer is a former member of the Energy and Planning Committee and the author of several books on the energy sector
Published in The Express Tribune, December 11y2023.
Likes Business on Facebook, He follows @TribuneBiz on Twitter to stay informed and join the conversation.
(Tags for translation) Elephant