Knowledge Nugget | Bitumen in Spotlight: Why ‘Black Gold’ behind India’s roads is making headlines

2. Bitumen, derived from crude oil, is mainly used as a binder in road construction where it holds together materials like sand, gravel, and crushed stone, to form asphalt. Waterproof, adhesive, and flexible, it helps roads withstand traffic load and various weather conditions. Thus, it is known as black gold in the pavement industry. 

3. Almost 85% of the paved roads in India are of flexible type and hence the research in the area of bitumen is soaring sky high. 

How is bitumen produced?

1. Crude oil is essentially a natural mixture of hydrocarbons such as methane, ethane and propane. It is heated at different temperatures to extract usable products.

2. In a refinery, crude oil is first heated to about 350-400°C to separate LPG, petrol, kerosene, diesel, jet fuel, and similar products. After this process, a large amount of residue collects at the bottom of the distillation column, which is called atmospheric residue.

3. The huge tower often seen in photos of refineries is the distillation column, while the large cylindrical tanks around it store products after distillation. This residue is then sent to a vacuum distillation unit, where the pressure is reduced to much lower than atmospheric pressure, so that very heavy hydrocarbons (vacuum gas oils) can vaporise at a lower temperature.

4. Under controlled conditions, the residue is further heated to 380-425°C and heavy Vacuum Gas Oils are removed. What remains is vacuum residue, also known as bitumen. It is further blended and adjusted to meet different viscosity specifications like VG-10, VG-30, VG-40, which are road-paving bitumens.

5. According to analysts, one tonne of crude oil can result in 3-8% (30-80 kg) of bitumen, depending on the type of oil. Light crude yields more petrol and diesel but very little bitumen. Heavy crude results in more vacuum residue and, therefore, more bitumen. It is stored in a tank at 150-170°C to keep it pumpable. 

How dependent is India on bitumen imports?

1. India requires almost 90 lakh tonnes of bitumen annually. Of this, around 54 lakh tonnes are produced domestically in the refineries of oil companies like IndianOil and Bharat Petroleum.

2. The shortfall is met by imports from West Asia. Over 99% of India’s bitumen imports come from Iraq, UAE, Iran, Oman and Bahrain.

3. Notably, India was not always as dependent on imports. The change has been driven by the mega road projects undertaken within the last decade, through schemes like Bharatmala (for enhancing road connectivity via expressways and economic corridors) and PMGSY.

4. National Highways have grown from 91,287 km in 2014 to 1.47 lakh km currently (a 61% increase), while the length of expressways increased from 93 km to 3,052 km. However, domestic bitumen production has not kept pace. Imports have more than doubled, and consumption increased by almost 50%.

5. According to data available with the Petroleum Planning and Analysis Cell of MoPNG, bitumen imports began in 2001-02, at around 9,000 tonnes. A significant increase was recorded in 2013-14, when 2.46 lakh tonnes were imported — more than double the previous year’s import volume. This doubled again by 2014-15, reaching 5.17 lakh tonnes, and continued increasing.

How is the West Asia conflict affecting Bitumen and PMGSY ?

1. The government has a target of building 10,000-km of highways in the ongoing financial year 2026-27. Additionally, 17,365 km of roads remain to be constructed under Pradhan Mantri Gram Sadak Yojana (PMGSY) Phase-III, a flagship scheme for rural infrastructure.

2. Bitumen imports have taken a hit after the  war, with road construction companies and contractors raising concerns over low supplies and increasing prices with the National Highway Authority of India (NHAI) and state road agencies.

3. According to the Ministry of Petroleum and Natural Gas (MoPNG) data, India imported 2.36 lakh tonnes of bitumen in April 2026, compared to 2.97 lakh tonnes imported in April 2025 and 2.74 lakh tonnes imported in April 2024.

The Ministry of Road Transport and Highways has granted relief measures of force majeure and price adjustment to highway contractors in light of war-related disruptions.

BEYOND THE NUGGET: Bio-bitumen as an alternative

1. To address stagnant domestic production and increasing imports, CSIR-Central Road Research Institute (CRRI) and CSIR-Indian Institute of Petroleum (IIP), Dehradun, have jointly developed a bio-bitumen technology which uses rice straw (parali) to produce Bio-oil. This is further blended to produce bio-bitumen.

2. The technology was unveiled on January 6. So far, three pilot test sections on National Highways have been laid to assess the suitability of bio-bitumen in road construction.

3. The government is projecting it as a dual solution to reduce import dependence and address winter pollution in northern India, where stubble burning is a contributor. It has also claimed that a 15% blending of bio-bitumen would save around Rs 4,500 crore in foreign exchange.

Post Read Question

 Consider the following statements, with reference to bitumen:

1. Bitumen is primarily obtained as a residue during the refining of crude oil.

2. Heavy crude oil generally yields more bitumen than light crude oil.

3. More than 90% of India’s bitumen imports come from countries in West Asia.

How many of the statements given above are correct?

(a) Only one

(b) Only two

(c) All three

(d) None

(Sources: Amid West Asia conflict, bitumen woes hit India’s road infrastructure push, How war in West Asia is taking a toll on India’s road construction push)

Subscribe to our UPSC newsletter. Stay updated with the latest UPSC articles by joining our Telegram channel – IndianExpress UPSC Hub, and follow us on Instagram and X.

🚨 Click Here to read the UPSC Essentials magazine for June 2026. Share your views and suggestions in the comment box or at manas.srivastava@indianexpress.com🚨